Aggrey Lelei Resume | Head Of Tech

Aggrey Kiplimo Lelei

Head Of Technology

Professional Summary

Head Of Tech & Senior Software engineer with 8+ years of leadership and engineering experience. Started career in Android and ERP development at Smart Web Kenya (2018–2019), delivering production applications and business systems. Joined Tiret Resorts (2020) and designed and built a cloud-native communication and logistics platform from scratch for NGO regional coordination. Pitched and delivered a major platform expansion, driving revenue growth, customer satisfaction, and increased regional engagement. Promoted to Head of Technology to lead platform scale-out and growing engineering needs. Lead a team of engineers: owning technical strategy, system architecture, and delivery. Improved NGO productivity and engagement by ~55%, supporting ~400 concurrent users with sub-150 ms latency at peak. Architect and operate Spring Boot–based distributed, event-driven services with strong observability and backpressure-aware processing. Integrated Embabel to enable agentic and retrieval-augmented workflows grounded in live system data.

Experience

Head of Technology

Tiret Resorts • Kenya

March 2023 - Present

Promoted to Principal Lead during platform scale-out and growing engineering needs, owning technical strategy, system architecture, and delivery while expanding managerial scope across recruiting, mentorship, and stakeholder alignment.

Technical Strategy & Architecture: Owned platform direction and system design for scale, improving NGO productivity and engagement by ~55% and increasing regional coordination impact through reliable platform execution.
Platform Expansion & Outcomes: Pitched and delivered a major platform expansion that drove revenue growth, improved customer satisfaction, and increased regional engagement through clearer workflows and stronger reliability.
People Leadership: Led a team of engineers; handled recruiting, onboarding, mentoring, and performance support while maintaining high engineering throughput and quality.
Performance & Scale: Supported ~400 concurrent users with sub-150 ms latency at peak, emphasizing fast user experiences and resilient operations.
Stakeholder & Shareholder Management: Took ownership of cross-functional alignment — translating business goals into technical plans, leading shareholder discussions, and communicating trade-offs, risk, and delivery timelines with clarity.
Agentic Context Engineering: Integrated Embabel to enable advanced agentic and retrieval-augmented workflows grounded in live system data, strengthening operational decision-making and accelerating support/coordination loops.

Senior Software Engineer

Tiret Resorts • Kenya

January 2020 - Feb 2023

Architected and delivered a cloud-native NGO communication and logistics platform from inception to production, owning system design, backend architecture, testing strategy, and long-term maintainability while leading day-to-day engineering execution.

Spring Boot Architecture Design: Designed a modular Spring Boot backend using layered architecture (Controller–Service–Repository), RESTful APIs, JPA/Hibernate, and secure authentication flows. Established clean package structures, configuration management, and scalable deployment foundations.
Platform from Scratch: Built core coordination, messaging, and logistics workflows end-to-end, translating business requirements into resilient domain models and production-grade backend services.
Testing & Code Quality: Implemented unit and integration testing (JUnit, Mockito), enforced code reviews and standards, and improved reliability through structured validation and regression coverage.
Maintenance & Optimization: Owned ongoing system maintenance, refactoring legacy modules, resolving production issues, improving performance, and ensuring long-term codebase sustainability.
Team Leadership: Mentored and unblocked junior engineers, improved development workflows, and maintained delivery discipline across the engineering lifecycle.

Android Software Engineer

Smart Web Kenya • Nairobi, Kenya

September 2017 - December 2019

Began career building and shipping production-grade Android applications, delivering end-to-end mobile features, integrating backend APIs, and ensuring stable releases for real-world client deployments.

End-to-End Android Development: Designed and implemented native Android applications using Java/Kotlin, following MVVM architecture, clean code principles, and modern Android SDK best practices.
API Integration & Data Handling: Integrated RESTful APIs, implemented JSON parsing, managed local persistence (Room/SQLite), and ensured efficient state management for reliable offline/online behavior.
UI/UX & Performance Optimization: Built responsive, user-friendly interfaces using XML layouts and Android components, optimized rendering performance, and reduced crashes through structured debugging and profiling.
Release & Production Stability: Managed build variants, signing configurations, Play Store deployment processes, and strengthened error handling to maintain stability in live environments.
Engineering Foundations: Developed strong fundamentals in debugging, performance tuning, modular code organization, and disciplined feature delivery forming the base for later backend and distributed systems work.

Technical Skills

Languages:Java Springboot (8+ years), Kotlin (7+ years), JavaScript/TypeScript (5+ years), Go (3+ years)

Event Streaming:Kafka

Enterprise AI Orchestration:Embabel, LangGraph

Cloud & Infrastructure:AWS (S3, EKS, MSK, ElastiCache, RDS, ECS, SQS, CloudWatch), Azure Cloud, Docker, k8s, Google Cloud Platform

Secret Management:HashiCorp Vault

Monitoring:Prometheus, Loki, Tempo, Alloy, Grafana

Projects

Sparrowx Platform - Distributed Social Backend with Agentic Intelligence

2025 – Present

📁 Source Code

A production-grade, microservice-based social platform inspired by Twitter, extended with an agentic intelligence layer using Embabel for planning, tool execution, and retrieval-augmented reasoning.

Distributed service architecture: Domain-driven microservices (Timeline, Tweet, Profile, Search) exposed via a unified API Gateway, using gRPC for low-latency, service-to-service communication.
Agentic Context Engineering at system scale: Implemented advanced retrieval-augmented workflows using Embabel + BGE Large with Elasticsearch and Qdrant, enabling context-aware reasoning over platform data and external documents.
Production reliability & security: Resilience4j for circuit breaking and rate limiting, Linkerd service mesh for mTLS and traffic control, and Vault for secure configuration management.
Observability & delivery: End-to-end tracing with Tempo, metrics via Prometheus, centralized logging with Loki, and GitOps-driven CI/CD using GitHub Actions.

Credentials

• IBM Blockchain Developer - Mastery Award (2018)• Bachelor's Degree in Computer Science - Jomo Kenyatta University Of Agriculture And Technology, Nairobi (2017)